Core chuck



1960 A. P. LIMBACH 2,956,757

CORE CHUCK Filed Feb. 12, 1957 INVENTOR ATTORNEY- A.PAUL LIMBACH ed i -a e M CORE CHUCK Anthony Paul Limbach, New Brunswick, N.J., assignor to Union Carbide Corporation, a corporation of New York Filed Feb. 12, 1957, 'Ser. No. 639,816

1 Claim. (Cl. 242-463) This invention relates to core chucks, and more particularly to chucks of this character for internally gripping on a windup or feed shaft hollow cores, such as those made from tubes of paper, wood, metal, and other materials and onto which sheet material such as plastic film is wound up into a roll.

The main objects of the invention are to provide a core chuck which has a positive grip to prevent slipping of the core either axially or circumferentially, and which is automatic in operation so that it merely slips in and out of a core without any tightening of collars or set screws.

According to the present invention, the core chuck comprises spring blades secured on opposite sides of a rotor and extending in opposite directions, and a collar surrounding the rotor having slots through which the outer ends of said blades extend, whereby rotation of the core relative to the rotor and collar in one direction bends the blades into slots, and relative rotation thereof in the opposite direction straightens the blades to extend them out through the slots.

'In the drawings:

Fig. 1 is an exploded perspective view of the chuck according to one embodiment of the present invention;

Fig. 2 is an assembly perspective view of the same;

Fig. 3 is a radial cross section through the chuck shown in Fig. 2;

Fig. 4 is an assembly perspective view of a modification of the invention for larger diameter cores; and

Fig. 5 is a detail of a blade for the chuck.

As shown in Fig. 1, the chuck comprises spring blades 12 secured on opposite sides of a rotor shown as a shaft and extending in opposite directions. Preferably the shaft 10 is grooved as at 14 to form a flat seat to which the bases of the spring blades 12 are secured by screws 15.

Surrounding the shaft 10 is a collar 16 having slots 18 substantially tangential to the shaft 10 and through which the blades 12 extend. In the form shown the collar 16 is slidable along the shaft to receive the blades 12 in the slots 18, after which the collar 16 is secured to the shaft by set screws 20. The blades 12 protrude only a short distance, about one-eighth of an inch beyond the collar 16, to avoid a long cantilever action and thereby minimize or eliminate injury to the blades. Both ends of the collar 16 are provided with a taper 19 for easy entrance into the core. Preferably a cover plate 22 surrounds and is slidable on the shaft into engagement with the collar 16 and secured thereto by screws 24 to close the sides of the slots 18. The cover plate 22 has substantially the same outside diameter as does the collar 16 against which it locks. When the core material is difficult to grip, the blades 12 may have serrated edges 25, as shown in Fig. 5, to improve the gripping action.

In the form shown in Fig. 4 provided for larger diameter cores, the blades 12 are secured to the rotor which Patented Oct. 18, 1960 is shown as a hub 27 secured to the shaftlll. 'In form the collar 16 is provided with a tapered leading edge 30 .for. easy entrance into the core, and a shoulder 28 against which the core abuts when slipped over the blades 12. A similar shoulder may be provided in the form shown in Fig. 1, if desired.

In operation when a core 26, as shown in Fig. 3, is slipped onto the chuck, the core is rotated counterclockwise. This bends down the two spring steel blades 12 into the slots so that the core passes over them. In the form shown in Fig. 4, the core passes over the blades 12 and abuts the shoulder 28.

When winding sheet material onto the core 26, the shaft 10 is driven counterclockwise which causes a rotation of the collar 16 relative to the core 26 tending to straighten the blades and cause them to dig into the inside of the core.

When the winding is concluded, for removal of the core, a slight counterclockwise twist thereof relative to the rotor is all that is necessary to bend the blades so that they release their grip on the inside of the core.

The cover plate 22 and collar 16 serve several purposes. First they support the blades in three directions, in fact in every direction excepting that in which play must be allowed to permit disengagement of the blade 12 from the core 26. They, therefore, take up axial thrust against the blades 12 while the core 26 is being mounted or dismounted, as well as back up the blades against the circumferential thrust which is exerted against the blades during drive. Second they positively and in a sense automatically position the core 26 with respect to the shaft 10, keep the core in parallel alignment with the shaft, and prevent skewing during operation.

The chuck shown in Fig. 4 preferably consists of only two pieces. The cover plate 22 is one piece and everything else is the second piece. The hub 27 and shouldered slotted collar 16 are a single casting. The blades 12 are mounted onto the hub portion by two bolts 34 which pass through the blade 12, hub 27, and opposing blade 12 in that order. These bolts do not pass through the shaft but pass through the hub 27 on either side of the shaft. A hole 32 on either side of the collar 16 provides access to said bolts 34 by an Allen wrench or the like. Once the blades are installed, the entire assembly rides freely along the shaft and can be locked in position thereon by a pair of set screws 20 in the shoulder portion.

Since the core abuts the shoulder 28 and does not pass over it, the set screws are always accessible and the chuck can be positioned even while the core is mounted for operation.

The chuck arrangement illustrated in Fig. 4 is generally preferred. For small cores about 3 inches or less in diameter space limitations make it impractical to employ the hub type blade mount and the form shown in Fig. 1 is employed.

What is claimed is:

Core chuck comprising a rotor, spring blades having bases rigidly and permanently secured on opposite sides of said rotor and extending in opposite directions, and t a thick annular collar surrounding and rigidly secured to said rotor and forming with said rotor a rigid unit having no relative movement of the parts thereof other than the bending of said blades, said collar having slots receiving said blades, said slots extending from the inside to the outside of said thick annular collar forming deep rear walls in alignment with said blade bases and normally abutting the rear sides of said blades with the outer ends of said blades extending beyond the outside of said thick Walled annular collar, whereby upon insertion of said rigid unit into a core to bring the outer ends of said blades into engagement with the inside of the core, and upon rotation of said rotor and collar rigid therewith as a unit relative to the core in one direction, the engagement of the inside of said core with the ends of said blades bends said blades into said slots, and upon relative rotation thereof in the opposite direction, the engagement of said core with the ends of said blades, straightens said blades into abutment with the deep rear walls of said slots to extend their ends out through said slots.

References Cited in the file of this patent UNITED STATES PATENTS Brown Apr. 2,

Kiracofe Mar. 13,

Melling May 15,

FOREIGN PATENTS Sweden Feb. 17, 

